| 1. | Experimentally , an interesting six - route ndr characteristic , resulting from the form of split miniband structures and the extension of high - field domain in the superlattice , is observed at room temperature 实验的结果显示,由于此分?迷你带结构及超晶格结构中高场区域的扩展,于常温下可观察出?道轨迹之多重负微分电阻特性。 |
| 2. | The " wavefront " domain decomposition method developed above is used in the division of flow field domain . the quantity of physics variables on the " subjunctive " boundary elements needs mutual communication of subdomains during the simulation 流场区域的划分采用改进的“波阵面”区域分裂算法, “虚拟”边界单元的物理量的计算由子区域之间相互通讯来完成,信息的发送方式采用“循环式”发送方式。 |
| 3. | For the requirement of more negative differential resistance ( ndr ) routes , three split quantized energies are formed in the four - period inp / ingaas superlattice structure with relatively thin ingaas quantum wells under ideal flat - band condition , and high - field domain in the superlattice is formed under sufficiently large operation bias 为获得?多轨迹的负微分电阻,本研究组件使用?相当薄之砷化铟镓?子井,可使四周期磷化铟/砷化铟镓超晶格结构在平带情况下形成三个分?的?子化能阶,且于足够大的操作偏压下在该超晶格结构中形成?高场区域。 |
| 4. | Based on the transferred - electron theory of the iii - v compound semiconductor and the research on the lock - on effect of the si - gaas pcss ' s , this paper proposes the monopole charge domain model similar to the guun or high - field domain to explain the peculiar switching phenomena occurring in the lock - on mode theoretically 本文基于gaas等?族化合物半导体的转移电子理论,结合半绝缘gaas光电导开关中特有的lock - on效应的研究,提出了类似于耿畴(高场畴或偶极畴)的单极电荷畴理论模型,对光电导开关lock - on效应的各种现象给出了理论解释。 |
| 5. | When the applied bias voltage is changed within positive slope regions of u - i curve , the domain boundary between the high and low electric field domains does not moved , and the size of electric field domains regions is also not altered , while the electric field strengths are adjusted 用模拟计算的方法研究了弱耦合掺杂gaaa / alas超晶格在时变电压下的场畴机制和固定偏压下电流自维持振荡。在时变电压下,一定掺杂的超晶格处于稳定的电场畴, u - i曲线呈现锯齿状波形。 |
| 6. | In addition , the breakdown and the degeneration of pcss " s are serious problems in the applications . in this dissertation the mode of luminous charge domain is perfected ulteriorly by deeply studying the dynamics characteristic of high - field domain of the trans - electron device with experiment stability of nonlinear pcss 本文在通过对转移电子器件偶极畴的动力学特征作了深入分析的基础上,结合非线性pcss ' s的稳定性实验,对非线性pcss ' s的光激发电荷畴理论模型作了进一步的完善。 |
| 7. | The electric field domains and current self - oscillations which result from sequential resonant tunneling between different subbands of the superlattice are very significant phenomena . we have optimized the simulation using matlab software . comparing the processing data , we know that various ode commands solve problems with different difficulties 本论文主要内容包括以下几个方面:运用matlab软件进行模拟计算的算法优化,从比较掺杂弱耦合gaas / alas超晶格模拟计算的过程数据可得,不同的ode命令可求解问题的难度是不同的:针对较低难度问题,即研究固定偏压下超晶格纵向输运的求解问题( du / dt = 0 ) ,一般首选ode45 。 |
| 8. | For the first current plateau , two kinds of sequential resonant tunneling of - process and - x process are observed in the wide barrier gaas / alas superlattice under various pressures for p < 2kbar , the high field domain is formed by - process , while for p > 2kbar , the high field domain is formed by - x process when the barrier width was decreased to 2nm , we found that ground - state - 对于宽垒( > 3 . 5nm )的gaaa / alas超晶格,当流体静压力超过临界压力2kbar后,平台宽度随压力的升高而收缩。对于窄垒( 2nm ) gaaa / alas超晶格, u - i曲线上的平台将不随压力变窄。 |
| 9. | Since the concept of superlattice was proposed , vertical transport in superlattice has been investigated widely . the electric field domains and current self - oscillations which result from sequential resonant tunneling between different subbands of the superlattice are very significant phenomena . such kind of oscillation can be uesd to make tunable microwave oscillaors . in this thesis , low temperature transport problem , especially the formation of field domain and the condition of current self - oscillations in doped gaas / alas superlattice with weak coupling are investigated thoroughly and also by combining the macroscopic model with the microscopic one . , the voltage - current characteristic and the current oscillation are simulated . the calculated result is nearly consistent with the experimental data 由超晶格中子能级之间的顺序多阱共振隧穿引起的电场畴及电流自维持振荡现象是其中的一个非常有意义的分支,该现象可用来制作电压调谐微波振荡器。本论文对弱耦合掺杂gaaa alas超晶格中的纵向输运特别是针对低温下的场畴的形成和固定偏压下电流自维持振荡产生的条件进行了深入的探讨,并结合宏观模型和微观模型对超晶格在时变电压作用下的电压-电流特性以及固定偏压作用下的电流特性进行了模拟计算。 |